A known connector for optical fiber is a one piece body of molded plastics material. A front end of the known connector has an aspheric lens the surface of which has an anti-reflective coating. The known connector has a holder in a cavity for aligning an end of the optical fiber axially with the lens surface. The end of the fiber is joined to the body by an adhesive. The adhesive and the body comprise optically transmissive materials having an index of refraction matching that of the fiber. Thereby, an optical signal emerging from the end of the optical fiber is transmitted successively through the adhesive and the body. The optical signal diverges until collimation by the lens surface and coating.
A requirement of the known connector is that the cavity, the holder and the lens must be in accurate axial alignment. The known connector is formed by moulding fluent plastics material internally of a set of dies of a moulding apparatus. One of the dies forms the aspheric lens of the known connector. A core pin of the apparatus is machined with a shape to form the cavity and holder. The core pin must be retained in desired axial alignment with the die that forms the lens, during the time that the fluent plastics material is introduced and solidified in the moulding apparatus. The core pin and the die are separate parts. When the dies open and move away from one another to allow removal of the moulded connector, the core pin is withdrawn relative to the die that forms the lens of the moulded connector. As a consequence, the axial alignment of the core pin and the die will vary each time fluent material is introduced and molded in the moulding apparatus.